Process for the production of aqueous dispersions of lipid spheres

Abstract

A process for producing a dispersion of spherules of a lipid compound encapsulating an aqueous phase includes admixing a water-dispersible lipid compound with an aqueous phase to be encapsulated in the spherules, agitating the resulting mixture to form a lamellar phase, adding a liquid dispersion phase and vigorously shaking the resulting mixture.

What is claimed is: 
     
       1. A process for producing a dispersion of spherules comprising arranged molecular layers of a lipid compound encapsulating an aqueous phase, the steps comprising (1) admixing at least one water-dispersible lipid compound having the formula X-Y wherein X represents a hydrophilic ionic or non-ionic group and Y represents a lipophilic group with an aqueous phase to be encapsulated in said spherules, said lipid compound having a lipophile group/hydrophile group ratio such that the lipid compound swells in the aqueous phase to be encapsulated therein so as to form a lamellar phase, (2) agitating the resulting mixture so that said lamellar phase is formed, (3) adding an aqueous liquid dispersion phase in an amount greater than the amount of lamellar phase obtained, said aqueous liquid dispersion phase being other than said aqueous phase being encapsulated so that when the resulting mixture is agitated the said lamellar phase is transformed into said spherules in the presence of said aqueous liquid dispersion phase, and (4) vigorously shaking the resulting mixture for a sufficient period of time. 
     
     
       2. The process of claim 1 wherein the weight ratio of the amount of aqueous phase to be encapsulated which is admixed with said lipid compound to the amount of lipid forming said lamellar phase is between about 0.1 and 3. 
     
     
       3. The process of claim 1 wherein the aqueous phase to be encapsulated is water or an aqueous solution of an active component. 
     
     
       4. The process of claim 1 wherein the weight ratio of the amount of said aqueous liquid dispersion phase to the amount of the lamellar phase dispersed therein is between about 2 to about 100. 
     
     
       5. The process of claim 1 wherein said aqueous liquid dispersion phase and the aqueous phase to be encapsulated are iso-osmotic. 
     
     
       6. The process of claim 1 wherein the resulting dispersion of spherules is submitted to an ultrasonic treatment. 
     
     
       7. The process of claim 1 wherein the lipid compound X-Y has a long, saturated or unsaturated, branched or linear lipophilic chain having from 12 to 30 carbon atoms. 
     
     
       8. The process of claim 1 wherein the lipid compound X-Y is a non-ionic compound selected from the group consisting of polyoxyethylenated fatty alcohols, linear or branched polyglycerol ethers, polyol esters and natural or synthetic glycolipids. 
     
     
       9. The process of claim 1 wherein the lipid compound X-Y is an ionic compound selected from the group consisting of amphoteric compounds having two lipophilic chains and compounds constituted by an association of two long chain organic ions of opposite signs. 
     
     
       10. The process of claim 1 wherein the lipid compound X-Y is a phospholipid. 
     
     
       11. The process of claim 1 wherein the lipid compound X-Y is sphingomyelin.